How To Clean Your Pyrex From An Expert On Glass

Give your old glassware a makeover with these cleaning tips.

This story originally appeared at Do You Remember by Jane Kenney.

How we clean our kitchenware is essential to keeping it looking good and lasting longer, especially when it comes to one particular kitchen item, Pyrex glassware. We all remember these classic kitchen containers from our childhood, and even today they’re still wildly popular. Pyrex should be handled with care, and with the right knowledge and product, preserving the integrity of Pyrex containers can help them to last more than a lifetime.

Stephen Koob, the Chief Conservator at The Corning Museum of Glass weighed in on the methods he uses for cleaning Pyrex glassware.

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Stephen Koob’s first rule is to never put Pyrex glassware in the dishwasher. Koob says the dishwasher does significant damage to a Pyrex container, as it often wears away at the beautiful design and it often doesn’t do that good of a job at cleaning the dish. His recommendation is to not put any glassware in the dishwasher!

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Glass can be damaged or scratched very easily, so Koob’s second tip is to avoid scrubbing sponges, even if it says ‘safe for glass’ or ‘non-scratch.’ He advises to not use any kind of utensils to scrape off caked or burnt-on foods. So what are we supposed to use? Koob has a solution.

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Start with warm water and a soft sponge or cotton towel. Use a clean detergent and wipe all stained surfaces on the glass container. If it’s not fully clean after being wiped, soak it in hot, soapy water overnight, then repeat the cleaning process the next day. If this still doesn’t work, there is one more option.


For the toughest of stains on your Pyrex glassware, Koob recommends a cleaning agent called Lye. Lye is a sodium hydroxide and contains very strong alkali, but should not be used in high concentrations. Koob recommends safety precautions when using Lye to clean glassware; you’ll need rubber gloves, a face mask, plastic goggles, a plastic tub, cotton balls, plastic brushes or a soft toothbrush, and a plastic apron.

Follow these step to clean Pyrex glassware with Lye:

  • Put on gloves, goggles, mask (if using), and apron.
  • Create a solution with approximately 2 teaspoons of Lye mixed into 6 ounces of water. Stir until dissolved. The solution will become warm to the touch as the chemical reaction takes place. Do not breathe in the fumes.
  • Place stained Pyrex into a plastic tub. Dip a soft brush into diluted Lye solution and gently rub over stains. Light stains should disappear quickly, while more set in stains, like burnt or caked-on food, may require two or three more applications of the Lye solution.
  • Between each cleaning, lift the Pyrex dish out of the plastic tub and rinse with warm water. The Lye solution need not sit on the dish longer than 20-30 seconds.
  • For more set-in stains, soak a cotton ball in the Lye solution and set it over the stain for 2 to 3 minutes, always keeping the Pyrex in the plastic container. Rinse with warm water and repeat, as needed.
  • Rinse with warm water once done with cleaning, along with the gloves, brushes, plastic tub, etc.

Note: Unused Lye solution may be saved in a plastic bottle. Be sure to label the Lye and the plastic bottle clearly to avoid improper use or poisoning. Use caution and know guidelines for pouring Lye down your drains.

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Again, use caution with this particular cleaning method, avoid contact with eyes, skin, or clothing. Dispose of the solution properly, clean up your tools and workspace, and properly label any unused Lye or Lye solution to avoid misuse.

With these steps and the necessary precautions for deep cleaning, it is possible to restore Pyrex glassware to its original glory.